In the related art, various types of apparatus have been proposed as a roof apparatus (for example, Japanese Patent No. 5219075 (Reference 1) and the like). As illustrated in FIG. 6, such a roof apparatus has a configuration in which a movable panel 91 and peripheral structures (hereinafter, referred to as a “sunroof unit 90”) thereof are assembled from below a vehicle. In this case, an opening 96 of a roof panel 95, which is opened and closed by the movable panel 91, is required to have an opening amount at which at least movements of the movable panel 91 in a height direction of the vehicle are allowed. For this reason, liquid tightness is ensured by a ring-shaped sealing member 92 attached along a peripheral portion of the movable panel 91 being elastically brought, by the movable panel 91 that is in a closed state, into contact with a tubular opening end 96a of the opening 96.
In a case of such a sealing structure, the possibility of the liquid leakage occurrence relatively increases by a contact surface of the sealing member 92 and the opening end 96a being extended in the height direction of the vehicle. Thus, measures, for example, adopting a complicated drainage structure, are required to be taken. Therefore, a sunroof unit that can be assembled from above the vehicle is desired. That is because such a sunroof unit ensures that the size of the movable panel does not restrict a substantial opening amount of the opening. That is, the possibility of the liquid leakage occurrence can be relatively lowered, for example, by the ring-shaped sealing member attached along the opening end of the opening being elastically brought into contact with the lower surface of the movable panel insofar as the opening amount corresponds to an amount at which the opening fits in an inner side of the movable panel that is in a closed state.